Technical Field
The disclosure relates to a semiconductor structure, and in particular it relates to a semiconductor structure that simultaneously includes a low-voltage MOS device and a high-voltage MOS device and method for manufacturing the same.
Description of the Related Art
Manufacturers of electronic goods are under constant pressure to supply devices with expanded functionality and lower prices. One example is the cell phone, where staunch competition between manufacturers and re-sellers has kept cell phone prices down even as cell phone functions have expanded dramatically. Indeed, cell phones now include such capabilities as e-mail, web-browsing, text-messaging, music storage, photography, and video playback.
In order to facilitate the trend towards expanded device functionality at lower prices, manufacturers must develop not only new processing architectures and algorithms, but also new semiconductor technologies allowing denser device integration at lower fabrication costs. However, increased device integration often requires a blending of heretofore incompatible technologies into a common device substrate.
Many electronic devices, such as the cell phone, include low-voltage CMOS devices in various circuitry (e.g., data encryption and decryption). However, the same electronic devices also include relatively high-voltage devices in another circuitry (e.g., modulators/demodulators and power amplifiers). Unfortunately, high-voltage devices do not generally function effectively at low voltages, and the low-voltage devices can be damaged by high voltages. These facts often result in the conventional provision of separate integrated circuits, one implemented in low-voltage devices and another implemented in high-voltage devices. However, such an approach to dealing with the common provision of different types of devices is simply not possible under emerging pressures related to integration densities and fabrication costs.
Many skills have been developed to overcome the problems cited above. However, the conventional skills that are often needed may entail the use of photomasks and that lithography processes be conducted. Accordingly, a novel structure for reducing the number of photomasks and lithography processes is called for.